Catalytic Hydrogenation of Cytotoxic Aldehydes Using Nicotinamide Adenine Dinucleotide (NADH) in Cell Growth Media

We demonstrate, for the first time, that pentamethylcyclopentadienyl (Cp*) iridium pyridinecarboxamidate complexes (5) can promote catalytic hydride transfer from nicotinamide adenine dinucleotide to aldehydes in pH 7.4 buffered cell growth media at 37 °C and in the presence of various biomolecules and metal ions. Stoichiometric hydride transfer studies suggest that the unique reactivity of 5, compared to other common Cp*Ir complexes, is at least in part due to the increased hydride transfer efficiency of its iridium hydride species 5-H. Complex 5 exhibits excellent reductase enzyme-like activity in the hydrogenation of cytotoxic aldehydes that have been implicated in a variety of diseases

Catalytic Hydrogenation of Cytotoxic Aldehydes Using Nicotinamide Adenine Dinucleotide (NADH) in Cell Growth Media

We demonstrate, for the first time, that pentamethylcyclopentadienyl (Cp*) iridium pyridinecarboxamidate complexes (<b>5</b>) can promote <i>catalytic</i> hydride transfer from nicotinamide adenine dinucleotide to aldehydes in pH 7.4 buffered cell growth media at 37 °C and in the presence of various biomolecules and metal ions. Stoichiometric hydride transfer studies suggest that the unique reactivity of <b>5</b>, compared to other common Cp*Ir complexes, is at least in part due to the increased hydride transfer efficiency of its iridium hydride species <b>5-H</b>. Complex <b>5</b> exhibits excellent reductase enzyme-like activity in the hydrogenation of cytotoxic aldehydes that have been implicated in a variety of diseases

Selective Acceptorless Dehydrogenation and Hydrogenation by Iridium Catalysts Enabling Facile Interconversion of Glucocorticoids

An iridium­(III) pentamethylcyclopentadienyl catalyst supported by 6,6′-dihydroxy-2,2′-bipyridine displays exquisite selectivity in acceptorless alcohol dehydrogenation of cyclic α,β-unsaturated alcohols over benzylic and aliphatic alcohols under mild aqueous reaction conditions. Hydrogenation of aldehydes and ketones occurs indiscriminately using the same catalyst under hydrogen, although chemoselectivity could be achieved when other potentially reactive carbonyl groups present are sterically inaccessible. This chemistry was demonstrated in the reversible hydrogenation and dehydrogenation of the A ring of glucocorticoids, despite the presence of other alcohol/or carbonyl functionalities in rings C and D. NMR studies suggest that an iridium­(III) hydride species is a key intermediate in both hydrogenation and dehydrogenation processes

Data_Sheet_1_Expression Profiles of 2 Phosphate Starvation-Inducible Phosphocholine/Phosphoethanolamine Phosphatases, PECP1 and PS2, in Arabidopsis.pdf

Phosphorus is essential for plant viability. Phosphate-starved plants trigger membrane lipid remodeling to replace membrane phospholipids by non-phosphorus galactolipids presumably to acquire scarce phosphate source. Phosphoethanolamine/phosphocholine phosphatase 1 (PECP1) and phosphate starvation-induced gene 2 (PS2) belong to an emerging class of phosphatase induced by phosphate starvation and dephosphorylates phosphocholine and phosphoethanolamine (PEtn) in vivo. However, detailed spatiotemporal expression pattern as well as subcellular localization has not been investigated yet. Here, by constructing transgenic plants harboring functional translational promoter–reporter fusion system, we showed the expression pattern of PECP1 and PS2 in different tissues and in response to phosphate starvation. Besides, the Venus fluorescent reporter revealed that both are localized at the ER. Characterization of transgenic plants that overexpress PECP1 or PS2 showed that their activity toward PEtn may be different in vivo. We suggest that PECP1 and PS2 are ER-localized phosphatases that show similar expression pattern yet have a distinct substrate specificity in vivo.</p